i'm trying to get a ill communication-era beastie boys sound out of the vocals, and I'm pretty sure that Green bullets are made for distortion. I want to save up for the Flagg mic, but it's 300 bucks and the bullet is 100. does anyone have any experience with them? do they feed back easily? It would run through a cranked fender champ that would be mic'd during shows

I'm super biased here but the Flagg Mic has better feedback rejection because it has a tight, directional pickup pattern. You can go out in front of the main speakers without feedback issues.

The green bullet is omni-directional and will tend to pickup sounds from a much greater distance which makes it more susceptible to unintentional sound coloration and feedback.

Also, the Flagg Mic has an XLR connection and will give gritty distortion on its own. If you'd like to use it with a guitar amp I suggest the Panic Mic ($179) instead which has a 1/4" and will function like a green bullet only with better feedback rejection.